Friction device.



PATENTED SEPT. 13, 1904.

L. A. SHEPARD.

FRICTION DEVICE.

APPLICATION FILED JAN. 23, 1902.

2 SHEETS-SHEET 2.

NO MODEL.

I 4 u q w. I I. I

n I A INVENTOR WITNESSES: .g/%@% No. 769,841. Patented September 13, 1904.

UNTT-En STATES PATENT Trice.

LOUIS A. SHEPARD, OF BROOKLYN, NEW YORK, ASSIGNOR TO CORNELIUS VANDERBILT, OF NEW YORK, N. Y.

FRICTION DEVICE.

SPECIFICATION forming part of Letters Patent No. 769,841, dated September 13, 1904.

Appli atio filed January 23, 1902. Serial No. 90,831. (No model.)

T a wh m it may concern.- Furthermore, they are especially serviceable Be it known that I, LoUIs A. SHEPARD, a and advantageousinthatthe frictional absorpcitizen of the United States, and aresident of tive and damping efiects produced by them the borough of Brooklyn, in the city and State increases as the shock which is to be broken 5 of New York, have invented new and useful increases, thus making them the most effect- Improvements in Friction Devices, of which ive when most needed. the following is a specification. I will now describe my invention, referring It is well known thatahelical or coil spring to the appended claims to show the actual 55 when subjected to sudden compression or tenscope thereof.

sion ordinarily vibrates a considerable num- Inthedrawings which accompany this speciber of times before coming to rest. This is fication, Figure 1 is a sectional view showing a decided disadvantage when such springs are my invention as applied to a draft-rigging. applied to railway-cars, especially in connec- Fig. 2 is a perspective view, partly in section, 60 tion with the draw-bar, as it produces a jerky of one of the friction members shown in Fig.

5 movement of the car whenever it is suddenly 1. Figs. 3, 5, and 5 are views similar to started or stopped, which is unpleasant to Fig. 1 and showing alternative constructions. passengers. It is very desirable that such a Fig. 4: is a perspective View of one of the spring should fulfil its function of absorbing, friction members shown in Fig. 3, and Fig. deadening, and minimizing sudden shocks or 6 is a sectional view showing one form of my blows by a single vibration, and in order to invention as applied to a buffer or supporting act in this way it is necessary that the action spring. of the spring should be deadened or damped In Figs. 1, 3, 5, and 5, 1 representsa drawin some way. In the operation. of a leafbar, and 2 the yoke thereof. In Fig. 1 are 7 spring this damping efiect is obtained by the shown two follower-plates 3 3, which are of F friction between adjacent leaves, and on this any ordinary form. Between the plates and account the action of a leaf-spring is more inclosing the ordinary coil spring or springs satisfactory in this respect than an ordinary are the cooperating members 5 and 6 of my helical or coil spring. friction device, which in this case are each 75 The object of my invention is to produce a formed of a single piece of metal. preferably 3 device or devices which will operate, by means spring-steel, in the form of a split tube flanged of friction, to absorb and gradually reduce at one end to form the bases 7 and 7, respecsudden shocks or blows, and, further, to pretively, against which the ends of the spring 4: vent or damp the excessive vibration of a bear. The open ends of these members when 80 helical spring, if such a spring is used in comin position are telescoped, as shown. Preferbination with the frictional resilient elements, ably the walls of these tubular pieces are not and thereby enable it to perform its functions of uniform thickness; but the thickness of in a much more satisfactory manner. each decreases from its base toward its end,

The devices in which I have embodied my thus causing said members to taper, the sec- 5 invention are very simple in structure and tional area between the exterior surfaces of 4 can therefore be produced at a small cost and the inner member increasing toward its base cannot become deranged. The frictional eleand the sectional area between the interior ments are resilient, and for this reason comsurfaces of the outer member decreasing tobine in themselves both spring and frictional ward its base. Thus it is seen that whenever 9 resistance to heavy blows or shocks and are, the follower-plates approach each other the moreover, self-adjusting for wear. They almember 5 is forced farther within the memlow no sudden recoil of the spring, as they ber 6. This necessitates that the walls of one act while the spring moves in either direction. or both these members shall yield. In the forms shown in Figs. 1 to 55, inclusive, the walls of the inner member yield inwardly, thus decreasing the sectional area between its exterior surfaces, while the walls of the'outer member yield outwardly, thus increasing the sectional area between its inner surfaces. The walls of these members being held at all times in' close contact by the resilience of the metal of which they are composed, the movement of the follower-plates is resisted by a constantlyincreasing friction. It is obvious that the amount of friction can be regulated by increasing or diminishing the angle or degree of inclination of the tapering members.

In the form shown in Figs. 3 and 4 the resilient friction members 5 and 6 are set into the follower-plates 3' 3' when cast and are firmly held thereby. Each member may be composed of two or more pieces set into the follower-plate, as indicated in dotted lines in Fig. 4C. In this form of the invention the walls are of uniform thickness; but they are inclined in such a manner with respect to the follower-plate that the sectional area between the exterior surfaces of the inner member gradually decreases from its base toward its end, while the sectional area between the interior surfaces of the outer member gradually increases from its base toward its end. This is clearly shown inFig. 3, and this construction will produce the same absorptive and dampening effect as the device shown in Fig. 1. Obviously the degree or amount of friction can easily be regulated by increasing or diminishing the angle at which the walls are set in the follower-plates.

It is evident that instead of using separate plates 3 3 the friction tubes may be cast integral with the follower-plates. By using a suitable grade of steel for casting the walls of the friction tubes or cups will be sufficiently elastic.

The friction members 5 and 6 (shown in Fig. 5) are secured to the follower-plates 3 3 by means of screws or other fastening devices '9, which engage lugs 8, integral with the follower-plates. The walls of these members may be either tapered, as shown in Fig. 5, or inclined, as in Fig. 3. Instead of these members being secured to the follower-plates they may be supported independently thereof, as shown in Fig. 5, by means of bolts 10 10, which pass through slots 11 11 in the yoke 2.

Another form in which my device may be em bodied is shown in Fig. 6. In this case the spring 15 is inclosed by the members 12 and I 14:, shown in the form of cups, and the friction device is situated within the spring. The member 12, which is preferably a malleableiron casting, has a tapering portion 13 integral therewith, which bears against the friction bearing-blocks 16 16, which may be of brass. The tubular piece 17 is of resilient material, preferably spring-steel, and is provided with the flange 18. The walls of this piece are of uniform thickness; but the elements of the interior surface of the blocks 16 converge, and the absorptive and damping effect is practically the same as in the other forms shown except that in this form only one of the cooperating friction members is resilient, while in the other forms both members are resilient. The advantages of this form are simplicity of structure and the fact that there is no frictional wear on the resilient tube 17 The blocks 16 may be readily replaced in case they become greatly worn. Ordinary wear, however, is automatically taken up by the resilience of the tube 17, as is also the case with the other forms shown.

I do not desire to limit my invention to its use in connection with draft-rigging or with a coil-spring, as it may be used in connection with buffing or supporting springs of all kinds and may also be used, if desired, as a buffer or support independently of any spring.

WVhile I have shown the resilient frictional members in the form of hollow tubes, yet the specification and claims are not intended to specify only a device which is circular in crosssection, as obviously the members claimed may be fiat, elliptical, square, polygonal, or of anyother suitable shape, and the said frictional members may be composed of any number of separate pieces suitably united.

While I have shown a spring as cooperating with the resilient frictional member s, yet I wish to be distinctly understood as not limiting my invention to the presence of a spring. Since the frictional members of my device are themselves resilient, the device may be used without any spring, and I believe that I am the first to devise a friction device comprising two cooperating frictional elements, one of which is split and one of which is composed of resilient or spring material.

Having thus described my invention, what I claim, and desire to secure by Letters Patent, is-

1. A friction device comprising a resilient hollow member having an inwardly-yielding spring-wall, cooperating with a member having an interior converging surface, substantially as described.

2. A friction device having a tapering, inwardly-yielding spring-wall,cooperating with IIO a member having an outwardly yieldingspring-wall whose interior surfaces are inclined toward each other, substantially as described.

3. A friction device comprising a radially compressible, resilient hollow member, cooperating with a member having an interior surface whose elements converge, substantially as described.

4. A friction device comprising a tapering, radially-compressible, resilient hollow member, cooperating with a radially-expansible,

resilient hollow member having an interior surface whose elements converge, substantially as described.

5. As a new article of manufacture, a draftrigging follower-plate carrying a radiallyexpansible resilient hollow member, the elements of whose interior surface converge, substantially as described.

6. As a new article of manufacture, a draftrigging follower-plate carrying a radiallycompressible resilient hollow chamber, the elements of whose exterior surface diverge, substantially as described.

7 In a draft-rigging, a member having a yieldingly-supported interior surface whose elements converge, a member having a yieldingly supported exterior surface bearing against said interior surface, and a spring opposing the approach of said members, substantially as described.

8. In a friction device, a hollow chamber which has a yielding, exterior friction-surface whose elements are diverging straight lines, and a member which has an interior frictionsurface whose elements are converging straight lines, substantially as described.

9. In a friction device, cooperating members, one of which has an exterior frictionsurface whose elements are diverging straight lines, and the other of which has a yielding, interior, tubular friction-surface whose elements are converging straight lines, substantially as described.

10. In a friction device, two cooperating members, one of which has a yielding exterior friction-surface whose elements are diverging straight lines, and the other of which has a yielding interior friction-surface whose elements are converging straight lines, substantially as described.

11. A friction member comprisinga single piece of spring metal in the form of a split tube, the elements of whose exterior surface diverge, substantially as described.

12. A friction member comprising a single piece of spring metal in the form of a split tube, the elements of whose interior surface converge, substantially as described.

13. A device of the character described comprising a series of resilient elements having inclined frictional surfaces, the surfaces on adjacent elements adapted when said series of elements are subjected to compression to be relatively moved through engagement with each other thereby placing said resilient elements under tension.

14:. A device of the character described comprising a series of resilient elements having under tension.

15. A device of the character described comprising an expansible resilient element and a compressible resilient element, said elements having complemental inclined engaging frictional surfaces.

16. In an apparatus of the character described, an open spring element having an inclined frictional surface adapted to be engaged by a similarly-inclined surface to impart tension to the element.

17. In an apparatus for the purpose specified, the combination with an elastic friction element of frusto-conical form, of a frustoconical part with which it cooperates and whereby it is put under elastic stress when they are forced together, and a spring for separating said parts, substantially as described.

18. In a friction device, the combination with an elastic friction element of frusto-conical form, of a frusto-conical part with which it cooperates and whereby it is put under elastic stress when they are forced toward each other, substantially as described.

19. In a friction device, the combination of a split annular friction element having an inclined frictional surface, and a second frictional element having a correspondingly-inclined surface engaging therewith.

20. In a draft-rigging for railway-cars, the combination with two follower-plates, of a friction device interposed between said follower-plates comprising an elastic friction elementhaving an inclined frictional surface, and a second frictional element having a correspohdingly-inclined surface engaging therewith.

21. In a draft-rigging for railway-cars, the combination with two follower-plates, of a friction device interposed between said follower-plates comprising an elastic friction element having an inclined frictional surface, and a second friction element having a correspondingly-inclined surface engaging therewith,and a spring for separating said follower-plates.

22. In a draft-rigging for railway-cars, the combination with two follower-plates, one of said follower-plates having a projecting annular flange, and the other of said follower-plates carrying an expansible friction element adapted to frictionally engage the Walls of said flange.

23. In a draft-rigging for railway-cars, the combination with two follower-plates, one of said follower-plates having a projecting annular flange, and the other of said follower-plates carrying an expansible friction element adapted to frictionally engage the walls of said flange, and a spring inclosed within said. parts for forcing the follower-plates apart.

24. A device of the character described comprising an expansible resilient split element and a compressibleresilient element, said elements having complemental inclined engaging frictional surfaces.

25. A device of the character described comprisingan expansible resilient element, and a engaged by a similarly-inclined surface to imcompressible resilient element, said elements part tenslon to said spllt spring element.

being split and having complemental inclined engaging frictional surfaces. LOUIS SHEPARD 5 26. A device of the character described c0m WVitnesses:

prising an open split spring element having A. H. WESTON,

an inclined frictional surface adapted to be JAMES J. Cosenovn. 

